1. Field of the Invention
The present invention relates generally to ocular surgery, and more specifically to an inter-ocular lens (IOL) insertion system, involving generating a powered delivery force for controlling of inter-ocular lens (IOL) insertion during an IOL implantation procedure.
2. Description of the Related Art
Phacoemulsification surgery has been successfully employed in the treatment of certain ocular problems, such as cataracts, and typically entails removing a cataract-damaged lens and implanting of an intraocular lens. Phacoemulsification surgery involves removal of the cataract-damaged lens utilizing a small incision at the edge of the cornea. Through the small incision, the surgeon creates an opening in the capsule, i.e. membrane that encapsulates the lens, and through the opening can remove unwanted lens material and insert a new lens.
During surgery, the surgeon can insert an ultrasonic probe, incorporated within a phacoemulsification handpiece, through the opening in the cornea and capsule, thereby accessing the damaged lens. The handpiece's ultrasonically actuated tip emulsifies the damaged lens for evacuation by the handpiece. After the damaged natural lens is completely removed, the handpiece tip is withdrawn from the eye. The surgeon may now implant an intraocular lens into the space made available in the capsule.
Current techniques for fabricating IOLs employ deformable polymeric materials such as acrylic, silicon, and hydrogel based materials, and the like. For example, Abbott Medical Optics Inc. (AMO) of Santa Ana, Calif., manufactures a brand of aspheric IOL using a single piece of acrylic material called the Tecnis® one piece IOL.
Further, when performing phacoemulsification surgical techniques, such as lens insertion, the deformable polymeric materials enable the surgeon to fold, roll, and manipulate the IOL in a manner sufficient to position and orient the lens for placement within an eye. Once positioned and oriented, the surgeon may manually deliver the configured lens from an insertion cartridge into the eye through a small incision. In general, the insertion cartridge is installed within an IOL insertion system, i.e. a separate delivery handpiece. The surgeon may insert the IOL manually using the IOL delivery handpiece through a delivery tube, in a manner similar to operating a hypodermic needle.
The material properties of flexible acrylic IOLs are highly dependent on the temperature of the surrounding environment, the size of the insertion cartridge, and the ability of a surgeon to provide the precise pressure or force necessary to insert the IOL. In general, the higher the temperature, the softer the IOL material becomes. A warmed IOL may become sufficiently soft, making it easier for the surgeon to fold and manipulate the IOL and deliver the IOL through a small cartridge and through the incision.
However, in general, as the size of the tube of the insertion cartridge is reduced, the delivery force required for implantation increases. A higher delivery force, such as that associated with current small cartridges, may be problematic for the surgeon to control. Any person employing such a device under even near ideal conditions may have difficulty performing IOL implantation using current cartridges in the presence of small ocular incisions.
Currently available manual insertion systems include the aforementioned syringe type and may alternately involve a screw mechanism. Many of these systems are limited in that they require two hands to properly operate. The syringe mechanism requires precision pressure modulation, difficult for almost anyone, while the screw type insertion system is relatively time consuming.
Based on the foregoing, it would be beneficial to offer a single handpiece design for operating an automated IOL insertion system configured for dynamic control of the insertion force, where the surgeon may complete the lens replacement procedure within a sterile field.
Thus there exists a need for a design that facilitates delivery of IOLs that overcomes the foregoing drawbacks present in previously known designs used in the ocular surgical environment.